Twitter won't let me upload a background?

[Skylar]

I don't know why, but recently Twitter won't let me upload a background. Well, they'll let me upload one, but not tile it. The backgrounds are the right size and everything, I've used them before and they worked perfectly, but Twitter is just being weird. This has been going on for about two weeks. I upload a background, but I can't tile it. When I click tile, it removes my background and uses the premade cloud one. Does anyone know how to fix this...? I even made two new accounts, but it's still not working.
Actually, I can't even upload a background anymore, let alone tile it. Even when I upload one, it just changes to the premade cloud one. I save it my background, too, but it's not working.